What Happens to the Brain following Anterior Temporal Lobe Resection?

Abstract

CommentaryMemory changes are a well-known effect of anterior temporal lobe resection (ATL). Most attention has focused on decreased postoperative memory functioning, with results of a metaanalysis demonstrating memory decline on neuropsychological tests of verbal memory in 44% of individuals undergoing dominant hemisphere ATL, with a rate of decline observed in only 20% of those patients undergoing ATL on the nondominant hemisphere (1). Numerous attempts have been made to predict which clinical and demographic factors might provide the best predictors for postoperative memory decline. There are also ongoing attempts to modify existing surgical procedures or develop new procedures with the aim of reducing the severity and extent of memory loss associated with most standard surgical approaches (2).Receiving much less attention, however, are those patients who exhibit an improvement in memory functioning following ATL. While general memory improvement has been noted in some studies, Novelly and colleagues were the first to identify this in patients undergoing ATL, a profile selective improvement of modality specific memory functioning associated with the hemisphere contralateral to surgery. In that study's analysis of group changes, the authors found that patients

One-year neuropsychological outcome after temporal lobe epilepsy surgery in large Czech sample: Search for factors contributing to memory decline

“…[ 6 ] However, much less attention is devoted to patients who show improved memory functioning after AMTR. [ 2 ] In our group of patients, memory performance (MQ) in AMTR and SAHE group was 1 SD and 0.5 SD below average, respectively. In accordance with other studies, more selective approaches were preferred in patients with relatively normal preoperative performance, because of the higher risk of cognitive decline after surgery.…”

“…Results of a meta-analysis demonstrated verbal memory decline in patients who underwent AMTR in dominant hemisphere. [ 2 , 32 ] In the left-sided temporal surgery patients, naming was impaired in 34% of cases, whereas scores increases were seen in only 4% of patients. As evidenced by the summary results on IQ, attention, and executive functioning, only a few patients showed declines after the surgery.…”